It's a big universe, and each crew had their own problems to focus on. How much interacting between DS9 and VOY could be expected?

I don't believe I raised interaction as an issue. I'm merely pointing out that there was little effort by the production staffs of both shows to keep them in the same narrative universe. Of course, the same could be said of the use of the Defiant and Worf in First Contact and the limited impact it had on DS9.